The relationship between acute alcohol intoxication and emotional response is fundamental to virtually all major theories of alcohol use, abuse, and dependence. Yet, despite this pivotal role, surprisingly little is known about the processes and mechanisms that underlie the link, or even the conditions under which alcohol can be expected to alter affective reactions. Our proposal applies sophisticated psychophysiological measures of affect and cognition, within the framework of a multi- dimensional-multi-level conceptualization of emotion, in an effort to advance understanding of the effects of acute alcohol intoxication on emotional response. Our extensive preliminary studies indicate that the impact of alcohol on affective responding occurs through its action on complex information processing abilities, rather than at the level of primitive motive systems representing basic appetitive and defensive dispositions. We propose five interrelated experimental analogue studies designed to extend evaluation of this hypothetical cognitive mediation of the alcohol-emotion nexus by focusing on potentially interactive psychological processes. Each involves use of the eyeblink component of the startle reflex to index the valence of ongoing "action dispositions" at frequent intervals and in connection with a variety of task manipulations designed to vary demands on cognitive resources that might by compromised by intoxication. The startle reflex is useful because it has been reliably shown that reactions to startle "probes" (sudden, intense, sensory stimuli such as loud noises) are affectively-modulated (i.e., potentiated when one is threatened, but attenuated when one anticipates reward). We also plan to employ the P300 component of ERP to track attentional processes simultaneous with the startle probe evaluations in several of the studies. Specific experiments are designed to contrast the negligible effects of alcohol on simple, explicit fear conditioning with its effective reduction of unpleasant affect when aversive cues are embedded in complex divided attention tasks, contextual associations, and passive- avoidance conflict situations. By assessing affective reactions and cognitive demands simultaneously we should also be able to draw meaningful inferences about the brain mechanisms underling alcohol's effects on emotion.